Elements of the philosophy of the human mind. By Dugald Stewart. Rev. and abridged, with critical and explanatory notes, for the use of colleges and schools. By Francis Bowen ...

212 THE INFLUENCE 0E CASUAL ASSOCIATIONS.
ages and nations, but is the very reverse of an association
which was once equally prevalent. It is observed by Dr.
Gregory, in the preface to his edition of Euclid's works, that
the more ancient of the Greek writers looked upon grave sounds
-is /tigh, and acutie ones as low; and that the present mode of
xpression on that subject was an innovation introduced at a
later period.*?
In the instances which have now been mentioned, our habits
of combining the notions of two things become so strong, that
we find it impossible to think of the one, without thinking at the
same time of the other. Various other examples of the same
species of combination, although, perhaps, not altogether so
striking in degree, might easily be collected from the subjects
about which our metaphysical speculations are employed. The
sensations, for instance, which are excited in the mind by external objects, and the perceptions of material qualities which follow
these sensations, are to be distinguished fiom each other only
by long habits of patient reflection. A clear conception of this
distinction may be regarded as the key to all Dr. Reid's reasonings concerning the process of nature in perception; and till it
has once been rendered familiar to the reader, a great part of
his writings must appear unsatisfactory and obscure. In truth,
our progress in the philosophy of the human mind depends
much more on that severe and discriminating judgment, which
- The association to which, in modern times, we are habituated from
our infancy, between the ideas of acute and high, and between those of
grave and low, is accounted for by Dr. Smith, in. his Harmonics, from the
fol'mation of the voice in singing; [the deep or grave sounds appearing to
come from the lower part of the throat, and the acute or sharp notes from
above.]
Dr. Beattie, in his ingenious essay on poetry and music, says it is probable that the deepest or gravest sound was called seumma by the Romans,
and the shrillest or acutest ina; and he conjectures, that " this might have
been owing to the construction of their instruments; the string that
sounded the former being perhaps highest in place, and that which
sounded the latter lowest." If this conjecture could be verified, it would
afford a proof from the fact, how liable the mind is to be influenced in
this respect by casual combinations.